Abstract: In this study, the adhesion of ice to solid substrates
with different surface properties is compared. Clear ice, similar to
atmospheric in-flight icing encounters, is accreted on the different
substrates under controlled conditions. The ice adhesion behavior is
investigated by means of a dynamic vibration testing technique with
an electromagnetic shaker initiating ice de-bonding in the interface
between the substrate and the ice. The results of the experiments
reveal that the affinity for ice accretion is significantly influenced by
the water contact angle of the respective sample.
Abstract: Evaporator is an important and widely used heat
exchanger in air conditioning and refrigeration industries. Different
methods have been used by investigators to increase the heat transfer
rates in evaporators. One of the passive techniques to enhance heat
transfer coefficient is the application of microfin tubes. The
mechanism of heat transfer augmentation in microfin tubes is
dependent on the flow regime of two-phase flow. Therefore many
investigations of the flow patterns for in-tube evaporation have been
reported in literatures. The gravitational force, surface tension and
the vapor-liquid interfacial shear stress are known as three dominant
factors controlling the vapor and liquid distribution inside the tube. A
review of the existing literature reveals that the previous
investigations were concerned with the two-phase flow pattern for
flow boiling in horizontal tubes [12], [9]. Therefore, the objective of
the present investigation is to obtain information about the two-phase
flow patterns for evaporation of R-134a inside horizontal smooth and
microfin tubes. Also Investigation of heat transfer during flow
boiling of R-134a inside horizontal microfin and smooth tube have
been carried out experimentally The heat transfer coefficients for
annular flow in the smooth tube is shown to agree well with Gungor
and Winterton-s correlation [4]. All the flow patterns occurred in the
test can be divided into three dominant regimes, i.e., stratified-wavy
flow, wavy-annular flow and annular flow. Experimental data are
plotted in two kinds of flow maps, i.e., Weber number for the vapor
versus weber number for the liquid flow map and mass flux versus
vapor quality flow map. The transition from wavy-annular flow to
annular or stratified-wavy flow is identified in the flow maps.
Abstract: The application of agro-industrial waste in Aluminum
Metal Matrix Composites has been getting more attention as they
can reinforce particles in metal matrix which enhance the strength
properties of the composites. In addition, by applying these agroindustrial
wastes in useful way not only save the manufacturing cost
of products but also reduce the pollutions on environment. This
paper represents a literature review on a range of industrial wastes
and their utilization in metal matrix composites. The paper describes
the synthesis methods of agro-industrial waste filled metal matrix
composite materials and their mechanical, wear, corrosion, and
physical properties. It also highlights the current application and
future potential of agro-industrial waste reinforced composites in
aerospace, automotive and other construction industries.